Alabama and Clemson have already staked claim for being college football's best teams of 2018. For the rest of the Bowl Subdivision, attention has already shifted to next season.

An early Top 25 for 2019 begins with the Crimson Tide and Tigers before following through a run of elite programs, including Georgia, Oklahoma, Texas and Ohio State. There's also room in this early glance for a handful of newcomers, led by Southern California and Nebraska teams coming off a losing season.

It's never too early to start thinking about what's next. Here's the USA TODAY Sports preview of what's ahead for college football in the fall.

1. Alabama

The Crimson Tide will have a Heisman Trophy favorite in quarterback Tua Tagovailoa, an outstanding collection of skill players and enough returning talent to overcome what should be another exodus of starters to the NFL. There's no reason why Alabama can't be the nation's most dominant team during the regular season.

2. Clemson

There will be a significant rebuild on defense, led by a new cast up front, but the Tigers will still have defensive coordinator Brent Venables. In other words, there's no reason for major concern. The offense will be unstoppable behind the arm of rising sophomore quarterback Trevor Lawrence and the feet of junior running back Travis Etienne.

Georgia still has an Alabama-size hurdle to overcome before winning a national championship. But the Bulldogs' recruiting has been outstanding, quarterback Jake Fromm will contend for All-America honors and the road through the SEC East isn't overly intimidating.

4. Oklahoma

Maybe the Sooners' new quarterback won't be the next Kyler Murray. Either way, picking this offense to suffer a big decline in production is betting against recent history. Where OU may take a step forward is on defense behind new coordinator Alex Grinch, formerly of Ohio State.

5. Texas

Eight new starters on defense is cause for some concern, though Tom Herman's recruiting and the overall direction of the program in the wake of the Sugar Bowl overshadows any worries over personnel. Quarterback Sam Ehlinger seems poised to explode on a national scale.

6. Ohio State

Ryan Day replaces Urban Meyer. A new quarterback, perhaps Georgia transfer Justin Fields, is waiting to replace Dwayne Haskins, who is headed for the NFL. All eyes will be on the Buckeyes as the program undergoes a huge transition. Still, Day's work with the offense and the program's wealth of talent suggests the move won't be too rocky.

7. Michigan

Shea Patterson's decision to return in 2019 is a huge win for an offense that desperately needs consistency under center. There will be a spotlight on Jim Harbaugh, who needs to deliver a win against the Buckeyes and make a run at the national title after struggling with the Wolverines' rivals through his first four seasons. But this could be a team that takes the next step in 2019.

Question marks may abound on offense, as always, and the loss of standout defenders will make it even harder to run with Tagovailoa and Alabama. But the Tigers will return a starting quarterback, most of its rotation on offense and many starters from a defense that leaned toward youth in 2018.

9. Washington

Transfer Jacob Eason, formerly of Georgia, will take over at quarterback and rank among the best in the Pac-12. Where UW has personnel issues is in the defensive backfield, a unit of major strength set for a rebuilding during the offseason. This is still the league's best team by a not-insignificant margin.

10. Texas A&M

The Aggies seem ready for takeoff after a very solid debut under Jimbo Fisher and his staff. After going 9-4 and reeling in a top-five recruiting class, A&M will begin 2019 expecting to crack double-digit wins and challenge for a New Year's Six bowl coming out of the SEC.

11. Oregon

Justin Herbert's decision to return for his senior season is joined by the best recruiting class in program history. Whether coach Mario Cristobal can polish Oregon into a title contender remains to be seen. On paper, however, the Ducks are the second-best team in the Pac-12 and a dark horse in the postseason chase.

12. Central Florida

UCF showed how its offense can shine even without quarterback McKenzie Milton at the controls. While notching yet another unbeaten regular season is a tall order, the Knights have the offense, skill talent and experience to romp through the American Athletic Conference and stand as the surest thing in the Group of Five.

13. Notre Dame

The Irish have important starters to replace at wide receiver, in the secondary and along the defensive line. Altogether, the roster doesn't seem strong enough to contend with college football's best for the national championship. This is still a team with a baseline of nine wins that could exceed that mark should the offense become even more two-dimensional.

How far the Gators go in Dan Mullen's second season depends on whether an offense that brings back starters at quarterback, running back and receiver can find the explosiveness that was elusive in 2018. If so, Florida could make a serious run at Georgia in the SEC East.

15. Southern California

Last season's awful finish might be a sign of things to come. It might also be an aberration, especially if Kliff Kingsbury ends up at the controls of the Trojans' offense. If so, this could be a team poised for a huge leap in production and a return to competitiveness in the Pac-12 chase.

16. Iowa

The Hawkeyes will be in good-to-great shape at offensive tackle, quarterback, edge rushing and in the secondary. There will be big names to replace at tight end and along the interior of the offensive line, but Iowa's track record at both positions lessens any worries over a shift in personnel. Iowa could be the best team in the Big Ten West.

17. Iowa State

Iowa State's offense will hand the reins to sophomore quarterback Brock Purdy, a rising star in the Big 12. The Cyclones' biggest calling card is coach Matt Campbell, who has won a reputation as one of the top young coaches in football.

18. Stanford

Stanford will be Stanford in 2019 — a team that will win nine or more games, battle for a New Year's Six bowl and play with a bruising physicality. As always, the Cardinal could upend Washington and win the Pac-12. At worst, this team will be a fixture in the national rankings.

19. Penn State

There are fair questions to be asked about whether Penn State has what it takes to climb atop the Big Ten and earn a spot in the national semifinals. A bigger question asks how capably the offense can replace Trace McSorley at quarterback and find answers for the handful of would-be-seniors set for the NFL draft.

20. Army

Army will have a friendly schedule to go with the powerful running game and rock-solid foundation laid by Jeff Monken and his coaching staff. Still, can the Knights match this year's win total? Maybe not, but be ready for this team to be a very real contender for a New Year's Six bowl.

21. Nebraska

It's only a matter of time for Nebraska. Behind Scott Frost and quarterback Adrian Martinez, look for the offense to explode. What the Cornhuskers need is to get bigger and stronger overall and develop far more consistency defensively. If so, this is a team that will at least double this year's wins.

22. Syracuse

There will be a slew of senior starters lost to graduation, notably at quarterback and on the offensive line. As a whole, the Orange will break in a number of contributors recruited by Dino Babers to fit his offensive system and look largely the same along the defensive line and in the secondary. Syracuse might not hit on 10 wins but this is still one of the best teams in the ACC.

23. Wisconsin

Wisconsin looks for a rebound after a relatively disappointing season defined by injuries. There is uncertainty at quarterback and new faces set to ascend to starting roles on the offensive line. By and large, though, the Badgers are a safe bet to win eight or nine games during the regular season and contend for the Big Ten West.

24. Boise State

Don't overthink it: Boise will be in the thick of the hunt for a national ranking. The biggest offseason debate will be at quarterback, where the Broncos need to replace a four-year starter in Brett Rypien, and perhaps at running back as the Broncos will lose Alexander Mattison to the NFL. Look for the defense to pick up the slack should the offense struggle during the transition.

25. Baylor

Baylor's chances hinge on whether coach Matt Rhule returns in 2019, as he could be a contender for NFL openings. But the program's trajectory — from one win in 2017 to seven this past year — says a big step forward is in the offing.

Alabama Crimson Tide quarterback Jalen Hurts walks to the locker room before the 2019 College Football Playoff Championship game against the Clemson Tigers at Levi's Stadium. Kirby Lee, USA TODAY Sports